1. Field of the Invention
The present invention relates to systems and fittings for the assembly of prefabricated building components and, more particularly, to a system for the surface alignment of prefabricated concrete wall panels which are suspended on the outer face of a building.
2. Description of the Prior Art
For the aesthetic appearance of a building, it is important that its outer wall elements be mounted with accurately aligned surfaces. In the case of prefabricated wall panels, each panel is suspended separately. Because of variations in the supporting structure, it is necessary to provide surface alignment means which may take the form of an alignment member extending from one wall panel into a matching cavity of the other wall panel. The alignment member is adjustable perpendicularly to the alignment plane, but free to move in that plane, thereby producing an alignment interaction without transmitting any loadbearing forces between vertically adjacent wall panels.
Such a wall panel alignment system is disclosed in the German Patent No. 22 19 185 which suggests the use of a vertical alignment pin which has a threaded upper portion rotatably engaged in a plastic socket of the upper wall panel and an eccentrically offset lower portion engaging an oblong opening in a mortise frame which is permanently anchored in the upper face of the lower wall panel. A counter-nut secures the rotational position of the adjustment pin in relation to the socket which is embedded in the lower face of the upper wall panel. By releasing the counter-nut and rotating the eccentric alignment pin, it is possible to transversely reposition the two wall panels in relation to each other within the range of eccentricity of the alignment pin.
One shortcoming of this prior art system is that it requires comparatively expensive fittings, including a threaded socket, a machined eccentric alignment pin and a welded mortise frame. Another shortcoming of this configuration is related to the risk of the counter-nut becoming loose at the plastic socket, under the application of lateral forces to the wall panels, with the result that the alignment pin may rotate and the surfaces of the two wall panels may move out of alignment.